Anyone who has trouble with a WBB sedan running smoothly and/or the center pickups binding in place can try the trick shown below. I have made a small linear spring out of thin styrene and bolted it in place so that it takes over entirely from the stock spring, pushing down on the top of the center pickup spindle, shoving the pickup roller firmly down on the center rail. The bolt holding its other end was already on the car: it held the front axle bearing retainer plate down along with a small brass washer to which the wire that "grounds" the car's electrics is attached to the frame. Here, I've moved the wire and washer to the rear for other reasons, but you could do this trick while leaving the washer and wire in place. You vary spring pressure by trimming the width of the plastic piece. Keep it very thin.
When the WBB sedans came out, I, along with some others here, reported occasional problems with the center pickups on them. My opinion then, and now, is that the center pickups are simply a very weak part of what is otherwise an inspired product design. The small springs are too weak and tend to somehow get off center or even pop out. The vertical pickup movement mechanism tends to jam or bind.
Having bought and worked on 14 of these puppies, I am definitely not a fan of these center pickups - but I no longer care that much: with electronic flywheels installed, they'll run smoothly with just one pickup working. But I make a habit of "repairing" the front center pickup on all, anyway, as here, just because it is so easy to do and then I know I will have one of the two that works well even if both stock mechanisms fail.
The photo below shows this car, a very nice IXO '56 Fairlane -- my WBB sedan conversion number eight. It has a tiny Thunderbird emblem on the front fenders so I added dual exhausts. Electronic flywheel, of course - it runs smooth as silk at as little as 12 scale mph.
A growing pile of stock bodies from the conversions so far. I feel I should get creative with them but can't think of anything to do with them yet.
